1. Field of the Invention
The present invention relates to content delivery networks.
2. Related Art
The emergence of a vast amount of digital content stored across networks, particularly the Internet, has led to an increase in bandwidth required to transmit information.
Typically to regulate bandwidth use and to facilitate faster delivery of content, content providers utilize content delivery networks to provide content requested by users. A content delivery network (CDN) is a collection of servers coupled together, across a network such as the Internet, that cooperate to deliver content to end users.
CDNs usually host third-party content. Content may include static content (e.g. static HTML pages, images, documents, software patches etc), streaming media (e.g. audio, real time video etc) and varying content services (e.g. directory service, e-commerce service, file transfer service etc.). Sources of content include large enterprises, web service providers, media companies and news broadcasters. User clients may interact with the CDN to obtain desired content. For instance a user may specify a request for content or a service provider of content through devices such as cell phones, PDAs, laptops, desktops and other devices that can retrieve content over network(s).
CDNs try to improve network performance by distributing content to content delivery node(s) located close to users. However, as the physical size of content increases, it becomes inefficient for a content delivery node to retrieve data repeatedly from content providers. Furthermore, size of digital storage needed by a content delivery node increases.
Different methods have been proposed to reduce the bandwidth used due to fetching of redundant data. In one method, known as delta coding, a user is provided differences (known as deltas) from data that was originally provided to the user. However, at the current rate of bandwidth growth, such methods to reduce bandwidth usage may prove to be ineffective in the future. For example, in a case where the size of a ‘delta’ is substantially large, delays may still occur in providing data to the user. Such delays may degrade user experience.
Systems and methods are needed that improve the performance of content delivery networks.